Ytterbium(III) Trifluoromethanesulfonate-Catalyzed Homoconjugate Addition Reactions of β-Ketoesters with Activated Cyclopropane Derivatives at High Pressure - Kotsuki, Hiyoshizo; Arimura, Koji; Maruzawa, Ryosuke; Ohshima, Reiji (Synlett, 1999)